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accessibility_bridge.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "accessibility_bridge.h"
6
7 #include <functional>
8 #include <utility>
9
10 #include "flutter/third_party/accessibility/ax/ax_tree_manager_map.h"
11 #include "flutter/third_party/accessibility/ax/ax_tree_update.h"
12 #include "flutter/third_party/accessibility/base/logging.h"
13
14 namespace flutter { // namespace
15
16 constexpr int kHasScrollingAction =
17 FlutterSemanticsAction::kFlutterSemanticsActionScrollLeft |
18 FlutterSemanticsAction::kFlutterSemanticsActionScrollRight |
19 FlutterSemanticsAction::kFlutterSemanticsActionScrollUp |
20 FlutterSemanticsAction::kFlutterSemanticsActionScrollDown;
21
22 // AccessibilityBridge
23 AccessibilityBridge::AccessibilityBridge()
24 : tree_(std::make_unique<ui::AXTree>()) {
25 event_generator_.SetTree(tree_.get());
26 tree_->AddObserver(static_cast<ui::AXTreeObserver*>(this));
27 ui::AXTreeData data = tree_->data();
28 data.tree_id = ui::AXTreeID::CreateNewAXTreeID();
29 tree_->UpdateData(data);
30 ui::AXTreeManagerMap::GetInstance().AddTreeManager(tree_->GetAXTreeID(),
31 this);
32 }
33
34 AccessibilityBridge::~AccessibilityBridge() {
35 event_generator_.ReleaseTree();
36 tree_->RemoveObserver(static_cast<ui::AXTreeObserver*>(this));
37 }
38
39 void AccessibilityBridge::AddFlutterSemanticsNodeUpdate(
40 const FlutterSemanticsNode2& node) {
41 pending_semantics_node_updates_[node.id] = FromFlutterSemanticsNode(node);
42 }
43
44 void AccessibilityBridge::AddFlutterSemanticsCustomActionUpdate(
45 const FlutterSemanticsCustomAction2& action) {
46 pending_semantics_custom_action_updates_[action.id] =
47 FromFlutterSemanticsCustomAction(action);
48 }
49
50 void AccessibilityBridge::CommitUpdates() {
51 // AXTree cannot move a node in a single update.
52 // This must be split across two updates:
53 //
54 // * Update 1: remove nodes from their old parents.
55 // * Update 2: re-add nodes (including their children) to their new parents.
56 //
57 // First, start by removing nodes if necessary.
58 std::optional<ui::AXTreeUpdate> remove_reparented =
59 CreateRemoveReparentedNodesUpdate();
60 if (remove_reparented.has_value()) {
61 tree_->Unserialize(remove_reparented.value());
62
63 std::string error = tree_->error();
64 if (!error.empty()) {
65 FML_LOG(ERROR) << "Failed to update ui::AXTree, error: " << error;
66 assert(false);
67 return;
68 }
69 }
70
71 // Second, apply the pending node updates. This also moves reparented nodes to
72 // their new parents if needed.
73 ui::AXTreeUpdate update{.tree_data = tree_->data()};
74
75 // Figure out update order, ui::AXTree only accepts update in tree order,
76 // where parent node must come before the child node in
77 // ui::AXTreeUpdate.nodes. We start with picking a random node and turn the
78 // entire subtree into a list. We pick another node from the remaining update,
79 // and keep doing so until the update map is empty. We then concatenate the
80 // lists in the reversed order, this guarantees parent updates always come
81 // before child updates. If the root is in the update, it is guaranteed to
82 // be the first node of the last list.
83 std::vector<std::vector<SemanticsNode>> results;
84 while (!pending_semantics_node_updates_.empty()) {
85 auto begin = pending_semantics_node_updates_.begin();
86 SemanticsNode target = begin->second;
87 std::vector<SemanticsNode> sub_tree_list;
88 GetSubTreeList(target, sub_tree_list);
89 results.push_back(sub_tree_list);
90 pending_semantics_node_updates_.erase(begin);
91 }
92
93 for (size_t i = results.size(); i > 0; i--) {
94 for (const SemanticsNode& node : results[i - 1]) {
95 ConvertFlutterUpdate(node, update);
96 }
97 }
98
99 // The first update must set the tree's root, which is guaranteed to be the
100 // last list's first node. A tree's root node never changes, though it can be
101 // modified.
102 if (!results.empty() && GetRootAsAXNode()->id() == ui::AXNode::kInvalidAXID) {
103 FML_DCHECK(!results.back().empty());
104
105 update.root_id = results.back().front().id;
106 }
107
108 tree_->Unserialize(update);
109 pending_semantics_node_updates_.clear();
110 pending_semantics_custom_action_updates_.clear();
111
112 std::string error = tree_->error();
113 if (!error.empty()) {
114 FML_LOG(ERROR) << "Failed to update ui::AXTree, error: " << error;
115 return;
116 }
117 // Handles accessibility events as the result of the semantics update.
118 for (const auto& targeted_event : event_generator_) {
119 auto event_target =
120 GetFlutterPlatformNodeDelegateFromID(targeted_event.node->id());
121 if (event_target.expired()) {
122 continue;
123 }
124
125 OnAccessibilityEvent(targeted_event);
126 }
127 event_generator_.ClearEvents();
128 }
129
130 std::weak_ptr<FlutterPlatformNodeDelegate>
131 AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID(
132 AccessibilityNodeId id) const {
133 const auto iter = id_wrapper_map_.find(id);
134 if (iter != id_wrapper_map_.end()) {
135 return iter->second;
136 }
137
138 return std::weak_ptr<FlutterPlatformNodeDelegate>();
139 }
140
141 const ui::AXTreeData& AccessibilityBridge::GetAXTreeData() const {
142 return tree_->data();
143 }
144
145 const std::vector<ui::AXEventGenerator::TargetedEvent>
146 AccessibilityBridge::GetPendingEvents() const {
147 std::vector<ui::AXEventGenerator::TargetedEvent> result(
148 event_generator_.begin(), event_generator_.end());
149 return result;
150 }
151
152 void AccessibilityBridge::OnNodeWillBeDeleted(ui::AXTree* tree,
153 ui::AXNode* node) {}
154
155 void AccessibilityBridge::OnSubtreeWillBeDeleted(ui::AXTree* tree,
156 ui::AXNode* node) {}
157
158 void AccessibilityBridge::OnNodeReparented(ui::AXTree* tree, ui::AXNode* node) {
159 }
160
161 void AccessibilityBridge::OnRoleChanged(ui::AXTree* tree,
162 ui::AXNode* node,
163 ax::mojom::Role old_role,
164 ax::mojom::Role new_role) {}
165
166 void AccessibilityBridge::OnNodeDataChanged(
167 ui::AXTree* tree,
168 const ui::AXNodeData& old_node_data,
169 const ui::AXNodeData& new_node_data) {
170 auto platform_view =
171 GetFlutterPlatformNodeDelegateFromID(new_node_data.id).lock();
172 if (platform_view) {
173 platform_view->NodeDataChanged(old_node_data, new_node_data);
174 }
175 }
176
177 void AccessibilityBridge::OnNodeCreated(ui::AXTree* tree, ui::AXNode* node) {
178 BASE_DCHECK(node);
179 id_wrapper_map_[node->id()] = CreateFlutterPlatformNodeDelegate();
180 id_wrapper_map_[node->id()]->Init(
181 std::static_pointer_cast<FlutterPlatformNodeDelegate::OwnerBridge>(
182 shared_from_this()),
183 node);
184 }
185
186 void AccessibilityBridge::OnNodeDeleted(ui::AXTree* tree,
187 AccessibilityNodeId node_id) {
188 BASE_DCHECK(node_id != ui::AXNode::kInvalidAXID);
189 if (id_wrapper_map_.find(node_id) != id_wrapper_map_.end()) {
190 id_wrapper_map_.erase(node_id);
191 }
192 }
193
194 void AccessibilityBridge::OnAtomicUpdateFinished(
195 ui::AXTree* tree,
196 bool root_changed,
197 const std::vector<ui::AXTreeObserver::Change>& changes) {
198 // The Flutter semantics update does not include child->parent relationship
199 // We have to update the relative bound offset container id here in order
200 // to calculate the screen bound correctly.
201 for (const auto& change : changes) {
202 ui::AXNode* node = change.node;
203 const ui::AXNodeData& data = node->data();
204 AccessibilityNodeId offset_container_id = -1;
205 if (node->parent()) {
206 offset_container_id = node->parent()->id();
207 }
208 node->SetLocation(offset_container_id, data.relative_bounds.bounds,
209 data.relative_bounds.transform.get());
210 }
211 }
212
213 std::optional<ui::AXTreeUpdate>
214 AccessibilityBridge::CreateRemoveReparentedNodesUpdate() {
215 std::unordered_map<int32_t, ui::AXNodeData> updates;
216
217 for (const auto& node_update : pending_semantics_node_updates_) {
218 for (int32_t child_id : node_update.second.children_in_traversal_order) {
219 // Skip nodes that don't exist or have a parent in the current tree.
220 ui::AXNode* child = tree_->GetFromId(child_id);
221 if (!child) {
222 continue;
223 }
224
225 // Flutter's root node should never be reparented.
226 assert(child->parent());
227
228 // Skip nodes whose parents are unchanged.
229 if (child->parent()->id() == node_update.second.id) {
230 continue;
231 }
232
233 // This pending update moves the current child node.
234 // That new child must have a corresponding pending update.
235 assert(pending_semantics_node_updates_.find(child_id) !=
236 pending_semantics_node_updates_.end());
237
238 // Create an update to remove the child from its previous parent.
239 int32_t parent_id = child->parent()->id();
240 if (updates.find(parent_id) == updates.end()) {
241 updates[parent_id] = tree_->GetFromId(parent_id)->data();
242 }
243
244 ui::AXNodeData* parent = &updates[parent_id];
245 auto iter = std::find(parent->child_ids.begin(), parent->child_ids.end(),
246 child_id);
247
248 assert(iter != parent->child_ids.end());
249 parent->child_ids.erase(iter);
250 }
251 }
252
253 if (updates.empty()) {
254 return std::nullopt;
255 }
256
257 ui::AXTreeUpdate update{
258 .tree_data = tree_->data(),
259 .nodes = std::vector<ui::AXNodeData>(),
260 };
261
262 for (std::pair<int32_t, ui::AXNodeData> data : updates) {
263 update.nodes.push_back(std::move(data.second));
264 }
265
266 return update;
267 }
268
269 // Private method.
270 void AccessibilityBridge::GetSubTreeList(const SemanticsNode& target,
271 std::vector<SemanticsNode>& result) {
272 result.push_back(target);
273 for (int32_t child : target.children_in_traversal_order) {
274 auto iter = pending_semantics_node_updates_.find(child);
275 if (iter != pending_semantics_node_updates_.end()) {
276 SemanticsNode node = iter->second;
277 GetSubTreeList(node, result);
278 pending_semantics_node_updates_.erase(iter);
279 }
280 }
281 }
282
283 void AccessibilityBridge::ConvertFlutterUpdate(const SemanticsNode& node,
284 ui::AXTreeUpdate& tree_update) {
285 ui::AXNodeData node_data;
286 node_data.id = node.id;
287 SetRoleFromFlutterUpdate(node_data, node);
288 SetStateFromFlutterUpdate(node_data, node);
289 SetActionsFromFlutterUpdate(node_data, node);
290 SetBooleanAttributesFromFlutterUpdate(node_data, node);
291 SetIntAttributesFromFlutterUpdate(node_data, node);
292 SetIntListAttributesFromFlutterUpdate(node_data, node);
293 SetStringListAttributesFromFlutterUpdate(node_data, node);
294 SetNameFromFlutterUpdate(node_data, node);
295 SetValueFromFlutterUpdate(node_data, node);
296 SetTooltipFromFlutterUpdate(node_data, node);
297 node_data.relative_bounds.bounds.SetRect(node.rect.left, node.rect.top,
298 node.rect.right - node.rect.left,
299 node.rect.bottom - node.rect.top);
300 node_data.relative_bounds.transform = std::make_unique<gfx::Transform>(
301 node.transform.scaleX, node.transform.skewX, node.transform.transX, 0,
302 node.transform.skewY, node.transform.scaleY, node.transform.transY, 0,
303 node.transform.pers0, node.transform.pers1, node.transform.pers2, 0, 0, 0,
304 0, 0);
305 for (auto child : node.children_in_traversal_order) {
306 node_data.child_ids.push_back(child);
307 }
308 SetTreeData(node, tree_update);
309 tree_update.nodes.push_back(node_data);
310 }
311
312 void AccessibilityBridge::SetRoleFromFlutterUpdate(ui::AXNodeData& node_data,
313 const SemanticsNode& node) {
314 const FlutterSemanticsFlags* flags = node.flags;
315 FML_DCHECK(flags) << "SemanticsNode::flags must not be null";
316 if (flags->is_button) {
317 node_data.role = ax::mojom::Role::kButton;
318 return;
319 }
320 if (flags->is_text_field && !flags->is_read_only) {
321 node_data.role = ax::mojom::Role::kTextField;
322 return;
323 }
324 if (flags->is_header) {
325 node_data.role = ax::mojom::Role::kHeader;
326 return;
327 }
328 if (flags->is_image) {
329 node_data.role = ax::mojom::Role::kImage;
330 return;
331 }
332 if (flags->is_link) {
333 node_data.role = ax::mojom::Role::kLink;
334 return;
335 }
336
337 if (flags->is_in_mutually_exclusive_group &&
338 flags->is_checked != FlutterCheckState::kFlutterCheckStateNone) {
339 node_data.role = ax::mojom::Role::kRadioButton;
340 return;
341 }
342 if (flags->is_checked != FlutterCheckState::kFlutterCheckStateNone) {
343 node_data.role = ax::mojom::Role::kCheckBox;
344 return;
345 }
346 if (flags->is_toggled != FlutterTristate::kFlutterTristateNone) {
347 node_data.role = ax::mojom::Role::kSwitch;
348 return;
349 }
350 if (flags->is_slider) {
351 node_data.role = ax::mojom::Role::kSlider;
352 return;
353 }
354 // If the state cannot be derived from the flutter flags, we fallback to group
355 // or static text.
356 if (node.children_in_traversal_order.empty()) {
357 node_data.role = ax::mojom::Role::kStaticText;
358 } else {
359 node_data.role = ax::mojom::Role::kGroup;
360 }
361 }
362
363 void AccessibilityBridge::SetStateFromFlutterUpdate(ui::AXNodeData& node_data,
364 const SemanticsNode& node) {
365 const FlutterSemanticsFlags* flags = node.flags;
366 FlutterSemanticsAction actions = node.actions;
367 if (flags->is_expanded == FlutterTristate::kFlutterTristateTrue) {
368 node_data.AddState(ax::mojom::State::kExpanded);
369 } else if (flags->is_expanded == FlutterTristate::kFlutterTristateFalse) {
370 node_data.AddState(ax::mojom::State::kCollapsed);
371 }
372 if (flags->is_text_field && !flags->is_read_only) {
373 node_data.AddState(ax::mojom::State::kEditable);
374 }
375 if (node_data.role == ax::mojom::Role::kStaticText &&
376 (actions & kHasScrollingAction) == 0 && node.value.empty() &&
377 node.label.empty() && node.hint.empty()) {
378 node_data.AddState(ax::mojom::State::kIgnored);
379 } else {
380 // kFlutterSemanticsFlagIsFocusable means a keyboard focusable, it is
381 // different from semantics focusable.
382 // TODO(chunhtai): figure out whether something is not semantics focusable.
383 node_data.AddState(ax::mojom::State::kFocusable);
384 }
385 }
386
387 void AccessibilityBridge::SetActionsFromFlutterUpdate(
388 ui::AXNodeData& node_data,
389 const SemanticsNode& node) {
390 FlutterSemanticsAction actions = node.actions;
391 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionTap) {
392 node_data.AddAction(ax::mojom::Action::kDoDefault);
393 }
394 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollLeft) {
395 node_data.AddAction(ax::mojom::Action::kScrollLeft);
396 }
397 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollRight) {
398 node_data.AddAction(ax::mojom::Action::kScrollRight);
399 }
400 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollUp) {
401 node_data.AddAction(ax::mojom::Action::kScrollUp);
402 }
403 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollDown) {
404 node_data.AddAction(ax::mojom::Action::kScrollDown);
405 }
406 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionIncrease) {
407 node_data.AddAction(ax::mojom::Action::kIncrement);
408 }
409 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionDecrease) {
410 node_data.AddAction(ax::mojom::Action::kDecrement);
411 }
412 // Every node has show on screen action.
413 node_data.AddAction(ax::mojom::Action::kScrollToMakeVisible);
414
415 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionSetSelection) {
416 node_data.AddAction(ax::mojom::Action::kSetSelection);
417 }
418 if (actions & FlutterSemanticsAction::
419 kFlutterSemanticsActionDidGainAccessibilityFocus) {
420 node_data.AddAction(ax::mojom::Action::kSetAccessibilityFocus);
421 }
422 if (actions & FlutterSemanticsAction::
423 kFlutterSemanticsActionDidLoseAccessibilityFocus) {
424 node_data.AddAction(ax::mojom::Action::kClearAccessibilityFocus);
425 }
426 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
427 node_data.AddAction(ax::mojom::Action::kCustomAction);
428 }
429 }
430
431 void AccessibilityBridge::SetBooleanAttributesFromFlutterUpdate(
432 ui::AXNodeData& node_data,
433 const SemanticsNode& node) {
434 FlutterSemanticsAction actions = node.actions;
435 const FlutterSemanticsFlags* flags = node.flags;
436 node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kScrollable,
437 actions & kHasScrollingAction);
438 node_data.AddBoolAttribute(
439 ax::mojom::BoolAttribute::kClickable,
440 actions & FlutterSemanticsAction::kFlutterSemanticsActionTap);
441 // TODO(chunhtai): figure out if there is a node that does not clip overflow.
442 node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kClipsChildren,
443 !node.children_in_traversal_order.empty());
444 node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kSelected,
445 flags->is_selected);
446 node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kEditableRoot,
447 flags->is_text_field && !flags->is_read_only);
448 // Mark nodes as line breaking so that screen readers don't
449 // merge all consecutive objects into one.
450 // TODO(schectman): When should a node have this attribute set?
451 // https://github.com/flutter/flutter/issues/118184
452 node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kIsLineBreakingObject,
453 true);
454 }
455
456 void AccessibilityBridge::SetIntAttributesFromFlutterUpdate(
457 ui::AXNodeData& node_data,
458 const SemanticsNode& node) {
459 const FlutterSemanticsFlags* flags = node.flags;
460 node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextDirection,
461 node.text_direction);
462
463 int sel_start = node.text_selection_base;
464 int sel_end = node.text_selection_extent;
465 if (flags->is_text_field && !flags->is_read_only && !node.value.empty()) {
466 // By default the text field selection should be at the end.
467 sel_start = sel_start == -1 ? node.value.length() : sel_start;
468 sel_end = sel_end == -1 ? node.value.length() : sel_end;
469 }
470 node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextSelStart, sel_start);
471 node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextSelEnd, sel_end);
472
473 if (node_data.role == ax::mojom::Role::kRadioButton ||
474 node_data.role == ax::mojom::Role::kCheckBox) {
475 node_data.AddIntAttribute(
476 ax::mojom::IntAttribute::kCheckedState,
477 static_cast<int32_t>(
478 (flags->is_checked == FlutterCheckState::kFlutterCheckStateMixed)
479 ? ax::mojom::CheckedState::kMixed
480 : (flags->is_checked == FlutterCheckState::kFlutterCheckStateTrue)
481 ? ax::mojom::CheckedState::kTrue
482 : ax::mojom::CheckedState::kFalse));
483 } else if (node_data.role == ax::mojom::Role::kSwitch) {
484 node_data.AddIntAttribute(
485 ax::mojom::IntAttribute::kCheckedState,
486 static_cast<int32_t>(
487 (flags->is_toggled == FlutterTristate::kFlutterTristateTrue)
488 ? ax::mojom::CheckedState::kTrue
489 : ax::mojom::CheckedState::kFalse));
490 }
491 }
492
493 void AccessibilityBridge::SetIntListAttributesFromFlutterUpdate(
494 ui::AXNodeData& node_data,
495 const SemanticsNode& node) {
496 FlutterSemanticsAction actions = node.actions;
497 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
498 std::vector<int32_t> custom_action_ids;
499 for (size_t i = 0; i < node.custom_accessibility_actions.size(); i++) {
500 custom_action_ids.push_back(node.custom_accessibility_actions[i]);
501 }
502 node_data.AddIntListAttribute(ax::mojom::IntListAttribute::kCustomActionIds,
503 custom_action_ids);
504 }
505 }
506
507 void AccessibilityBridge::SetStringListAttributesFromFlutterUpdate(
508 ui::AXNodeData& node_data,
509 const SemanticsNode& node) {
510 FlutterSemanticsAction actions = node.actions;
511 if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
512 std::vector<std::string> custom_action_description;
513 for (size_t i = 0; i < node.custom_accessibility_actions.size(); i++) {
514 auto iter = pending_semantics_custom_action_updates_.find(
515 node.custom_accessibility_actions[i]);
516 BASE_DCHECK(iter != pending_semantics_custom_action_updates_.end());
517 custom_action_description.push_back(iter->second.label);
518 }
519 node_data.AddStringListAttribute(
520 ax::mojom::StringListAttribute::kCustomActionDescriptions,
521 custom_action_description);
522 }
523 }
524
525 void AccessibilityBridge::SetNameFromFlutterUpdate(ui::AXNodeData& node_data,
526 const SemanticsNode& node) {
527 node_data.SetName(node.label);
528 }
529
530 void AccessibilityBridge::SetValueFromFlutterUpdate(ui::AXNodeData& node_data,
531 const SemanticsNode& node) {
532 node_data.SetValue(node.value);
533 }
534
535 void AccessibilityBridge::SetTooltipFromFlutterUpdate(
536 ui::AXNodeData& node_data,
537 const SemanticsNode& node) {
538 node_data.SetTooltip(node.tooltip);
539 }
540
541 void AccessibilityBridge::SetTreeData(const SemanticsNode& node,
542 ui::AXTreeUpdate& tree_update) {
543 const FlutterSemanticsFlags* flags = node.flags;
544 // Set selection of the focused node if:
545 // 1. this text field has a valid selection
546 // 2. this text field doesn't have a valid selection but had selection stored
547 // in the tree.
548 if (flags->is_text_field &&
549 flags->is_focused == FlutterTristate::kFlutterTristateTrue) {
550 if (node.text_selection_base != -1) {
551 tree_update.tree_data.sel_anchor_object_id = node.id;
552 tree_update.tree_data.sel_anchor_offset = node.text_selection_base;
553 tree_update.tree_data.sel_focus_object_id = node.id;
554 tree_update.tree_data.sel_focus_offset = node.text_selection_extent;
555 tree_update.has_tree_data = true;
556 } else if (tree_update.tree_data.sel_anchor_object_id == node.id) {
557 tree_update.tree_data.sel_anchor_object_id = ui::AXNode::kInvalidAXID;
558 tree_update.tree_data.sel_anchor_offset = -1;
559 tree_update.tree_data.sel_focus_object_id = ui::AXNode::kInvalidAXID;
560 tree_update.tree_data.sel_focus_offset = -1;
561 tree_update.has_tree_data = true;
562 }
563 }
564
565 if (flags->is_focused == FlutterTristate::kFlutterTristateTrue &&
566 tree_update.tree_data.focus_id != node.id) {
567 tree_update.tree_data.focus_id = node.id;
568 tree_update.has_tree_data = true;
569 } else if (flags->is_focused != FlutterTristate::kFlutterTristateTrue &&
570 tree_update.tree_data.focus_id == node.id) {
571 tree_update.tree_data.focus_id = ui::AXNode::kInvalidAXID;
572 tree_update.has_tree_data = true;
573 }
574 }
575
576 AccessibilityBridge::SemanticsNode
577 AccessibilityBridge::FromFlutterSemanticsNode(
578 const FlutterSemanticsNode2& flutter_node) {
579 SemanticsNode result;
580 result.id = flutter_node.id;
581 FML_DCHECK(flutter_node.flags2)
582 << "FlutterSemanticsNode2::flags2 must not be null";
583
584 result.flags = flutter_node.flags2;
585 result.actions = flutter_node.actions;
586 result.text_selection_base = flutter_node.text_selection_base;
587 result.text_selection_extent = flutter_node.text_selection_extent;
588 result.scroll_child_count = flutter_node.scroll_child_count;
589 result.scroll_index = flutter_node.scroll_index;
590 result.scroll_position = flutter_node.scroll_position;
591 result.scroll_extent_max = flutter_node.scroll_extent_max;
592 result.scroll_extent_min = flutter_node.scroll_extent_min;
593 if (flutter_node.label) {
594 result.label = std::string(flutter_node.label);
595 }
596 if (flutter_node.hint) {
597 result.hint = std::string(flutter_node.hint);
598 }
599 if (flutter_node.value) {
600 result.value = std::string(flutter_node.value);
601 }
602 if (flutter_node.increased_value) {
603 result.increased_value = std::string(flutter_node.increased_value);
604 }
605 if (flutter_node.decreased_value) {
606 result.decreased_value = std::string(flutter_node.decreased_value);
607 }
608 if (flutter_node.tooltip) {
609 result.tooltip = std::string(flutter_node.tooltip);
610 }
611 result.text_direction = flutter_node.text_direction;
612 result.rect = flutter_node.rect;
613 result.transform = flutter_node.transform;
614 if (flutter_node.child_count > 0) {
615 result.children_in_traversal_order = std::vector<int32_t>(
616 flutter_node.children_in_traversal_order,
617 flutter_node.children_in_traversal_order + flutter_node.child_count);
618 }
619 if (flutter_node.custom_accessibility_actions_count > 0) {
620 result.custom_accessibility_actions = std::vector<int32_t>(
621 flutter_node.custom_accessibility_actions,
622 flutter_node.custom_accessibility_actions +
623 flutter_node.custom_accessibility_actions_count);
624 }
625 return result;
626 }
627
628 AccessibilityBridge::SemanticsCustomAction
629 AccessibilityBridge::FromFlutterSemanticsCustomAction(
630 const FlutterSemanticsCustomAction2& flutter_custom_action) {
631 SemanticsCustomAction result;
632 result.id = flutter_custom_action.id;
633 result.override_action = flutter_custom_action.override_action;
634 if (flutter_custom_action.label) {
635 result.label = std::string(flutter_custom_action.label);
636 }
637 if (flutter_custom_action.hint) {
638 result.hint = std::string(flutter_custom_action.hint);
639 }
640 return result;
641 }
642
643 void AccessibilityBridge::SetLastFocusedId(AccessibilityNodeId node_id) {
644 if (last_focused_id_ != node_id) {
645 auto last_focused_child =
646 GetFlutterPlatformNodeDelegateFromID(last_focused_id_);
647 if (!last_focused_child.expired()) {
648 DispatchAccessibilityAction(
649 last_focused_id_,
650 FlutterSemanticsAction::
651 kFlutterSemanticsActionDidLoseAccessibilityFocus,
652 {});
653 }
654 last_focused_id_ = node_id;
655 }
656 }
657
658 AccessibilityNodeId AccessibilityBridge::GetLastFocusedId() {
659 return last_focused_id_;
660 }
661
662 gfx::NativeViewAccessible AccessibilityBridge::GetNativeAccessibleFromId(
663 AccessibilityNodeId id) {
664 auto platform_node_delegate = GetFlutterPlatformNodeDelegateFromID(id).lock();
665 if (!platform_node_delegate) {
666 return nullptr;
667 }
668 return platform_node_delegate->GetNativeViewAccessible();
669 }
670
671 gfx::RectF AccessibilityBridge::RelativeToGlobalBounds(const ui::AXNode* node,
672 bool& offscreen,
673 bool clip_bounds) {
674 return tree_->RelativeToTreeBounds(node, gfx::RectF(), &offscreen,
675 clip_bounds);
676 }
677
678 ui::AXNode* AccessibilityBridge::GetNodeFromTree(
679 ui::AXTreeID tree_id,
680 ui::AXNode::AXID node_id) const {
681 return GetNodeFromTree(node_id);
682 }
683
684 ui::AXNode* AccessibilityBridge::GetNodeFromTree(
685 ui::AXNode::AXID node_id) const {
686 return tree_->GetFromId(node_id);
687 }
688
689 ui::AXTreeID AccessibilityBridge::GetTreeID() const {
690 return tree_->GetAXTreeID();
691 }
692
693 ui::AXTreeID AccessibilityBridge::GetParentTreeID() const {
694 return ui::AXTreeIDUnknown();
695 }
696
697 ui::AXNode* AccessibilityBridge::GetRootAsAXNode() const {
698 return tree_->root();
699 }
700
701 ui::AXNode* AccessibilityBridge::GetParentNodeFromParentTreeAsAXNode() const {
702 return nullptr;
703 }
704
705 ui::AXTree* AccessibilityBridge::GetTree() const {
706 return tree_.get();
707 }
708
709 ui::AXPlatformNode* AccessibilityBridge::GetPlatformNodeFromTree(
710 const ui::AXNode::AXID node_id) const {
711 auto platform_delegate_weak = GetFlutterPlatformNodeDelegateFromID(node_id);
712 auto platform_delegate = platform_delegate_weak.lock();
713 if (!platform_delegate) {
714 return nullptr;
715 }
716 return platform_delegate->GetPlatformNode();
717 }
718
719 ui::AXPlatformNode* AccessibilityBridge::GetPlatformNodeFromTree(
720 const ui::AXNode& node) const {
721 return GetPlatformNodeFromTree(node.id());
722 }
723
724 ui::AXPlatformNodeDelegate* AccessibilityBridge::RootDelegate() const {
725 return GetFlutterPlatformNodeDelegateFromID(GetRootAsAXNode()->id())
726 .lock()
727 .get();
728 }
729
730 } // namespace flutter
platform_view
std::unique_ptr< flutter::PlatformViewIOS > platform_view
Definition: FlutterEnginePlatformViewTest.mm:68
flutter::AccessibilityBridge::GetTree
ui::AXTree * GetTree() const override
Definition: accessibility_bridge.cc:705
flutter::AccessibilityBridge::RootDelegate
ui::AXPlatformNodeDelegate * RootDelegate() const override
Definition: accessibility_bridge.cc:724
flutter::AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID
std::weak_ptr< FlutterPlatformNodeDelegate > GetFlutterPlatformNodeDelegateFromID(AccessibilityNodeId id) const
Get the flutter platform node delegate with the given id from this accessibility bridge....
Definition: accessibility_bridge.cc:131
flutter::AccessibilityBridge::CreateFlutterPlatformNodeDelegate
virtual std::shared_ptr< FlutterPlatformNodeDelegate > CreateFlutterPlatformNodeDelegate()=0
Creates a platform specific FlutterPlatformNodeDelegate. Ownership passes to the caller....
flutter::AccessibilityBridge::AddFlutterSemanticsNodeUpdate
void AddFlutterSemanticsNodeUpdate(const FlutterSemanticsNode2 &node)
Adds a semantics node update to the pending semantics update. Calling this method alone will NOT upda...
Definition: accessibility_bridge.cc:39
flutter::AccessibilityBridge::AddFlutterSemanticsCustomActionUpdate
void AddFlutterSemanticsCustomActionUpdate(const FlutterSemanticsCustomAction2 &action)
Adds a custom semantics action update to the pending semantics update. Calling this method alone will...
Definition: accessibility_bridge.cc:44
flutter::AccessibilityBridge::GetPlatformNodeFromTree
ui::AXPlatformNode * GetPlatformNodeFromTree(const ui::AXNode::AXID node_id) const override
Definition: accessibility_bridge.cc:709
flutter::AccessibilityBridge::GetAXTreeData
const ui::AXTreeData & GetAXTreeData() const
Get the ax tree data from this accessibility bridge. The tree data contains information such as the i...
Definition: accessibility_bridge.cc:141
flutter::AccessibilityBridge::GetParentTreeID
ui::AXTreeID GetParentTreeID() const override
Definition: accessibility_bridge.cc:693
flutter::AccessibilityBridge::GetRootAsAXNode
ui::AXNode * GetRootAsAXNode() const override
Definition: accessibility_bridge.cc:697
flutter::AccessibilityBridge::~AccessibilityBridge
~AccessibilityBridge()
Definition: accessibility_bridge.cc:34
flutter::AccessibilityBridge::GetParentNodeFromParentTreeAsAXNode
ui::AXNode * GetParentNodeFromParentTreeAsAXNode() const override
Definition: accessibility_bridge.cc:701
flutter::AccessibilityBridge::AccessibilityBridge
AccessibilityBridge()
Creates a new instance of a accessibility bridge.
Definition: accessibility_bridge.cc:23
flutter::AccessibilityBridge::OnAccessibilityEvent
virtual void OnAccessibilityEvent(ui::AXEventGenerator::TargetedEvent targeted_event)=0
Handle accessibility events generated due to accessibility tree changes. These events are needed to b...
flutter::AccessibilityBridge::GetTreeID
ui::AXTreeID GetTreeID() const override
Definition: accessibility_bridge.cc:689
flutter::AccessibilityBridge::GetPendingEvents
const std::vector< ui::AXEventGenerator::TargetedEvent > GetPendingEvents() const
Gets all pending accessibility events generated during semantics updates. This is useful when decidin...
Definition: accessibility_bridge.cc:146
flutter::AccessibilityBridge::CommitUpdates
void CommitUpdates()
Flushes the pending updates and applies them to this accessibility bridge. Calling this with no pendi...
Definition: accessibility_bridge.cc:50
flutter::AccessibilityBridge::GetNodeFromTree
ui::AXNode * GetNodeFromTree(const ui::AXTreeID tree_id, const ui::AXNode::AXID node_id) const override
Definition: accessibility_bridge.cc:678
flutter::FlutterPlatformNodeDelegate::OwnerBridge::DispatchAccessibilityAction
virtual void DispatchAccessibilityAction(AccessibilityNodeId target, FlutterSemanticsAction action, fml::MallocMapping data)=0
Dispatch accessibility action back to the Flutter framework. These actions are generated in the nativ...
accessibility_bridge.h
flutter
Definition: accessibility_bridge.h:26
flutter::kHasScrollingAction
constexpr int kHasScrollingAction
Definition: accessibility_bridge.cc:16
flutter::AccessibilityNodeId
ui::AXNode::AXID AccessibilityNodeId
Definition: flutter_platform_node_delegate.h:15